Biodegradable textiles, masterbatches, and method of making biodegradable fibers

ABSTRACT

A masterbatch is disclosed, along with associated methods, and biodegradable filaments, fibers, yarns and fabrics. The masterbatch includes 0.2 to 5 mass % CaCO 3 , an aliphatic polyester with a repeat unit having from two to six carbons in the chain between ester groups, with the proviso that the 2 to 6 carbons in the chain do not include side chain carbons, and a carrier polymer selected from the group consisting of PET, nylon, other thermoplastic polymers, and combinations thereof.

The present invention relates to polymer compositions suitable fortextiles and that are also biodegradable in a reasonable helpfully shorttime span as compared to most common polymers.

BACKGROUND

Textiles are fundamental to human culture and have been made and used byhumans for thousands of years. The earliest textiles were—and continueto be—woven from natural fibers such as flax, wool, silk, and cotton.More recently, textile fibers, yarns and fabrics also have beenindustrially produced from polymers, such as polyester, nylon olefins,other thermoplastic polymers, and combinations thereof. Many modernpolymers can be made into an almost endless variety of shapes andproducts that are attractive, durable, and water-resistant. In manycases these synthetic fibers or yarns (depending upon the desiredtechnique and end product) can be blended with natural fibers to obtainend products with desired features of both natural and syntheticmaterials.

Although durability and water-resistance are desirable, these sameproperties can lead to secondary environmental problems. Textilesproduced from polymeric fibers do not naturally biodegrade in the samemanner as natural fibers such as cotton and wool, and can remain inlandfills and water (e.g., lakes, oceans) for hundreds of years or more.According to the United States Environmental Protection Agency, almost44 million pounds of synthetic (polymeric) textiles go to landfills on adaily basis. In addition, a large portion of the microfibers that arereleased from garments during the laundry wash cycle get caught in wastewater treatment plant sludge. The sludge is eventually turned out asbiosolids that are sent to landfill or used as fertilizer. Thesepolymeric microfibers then accumulate in soil or other groundenvironments, and may even become mobile, eventually making their wayfrom terrestrial to aquatic environments. According to some estimates,around half a million tons of plastic microfibers resulting from thewashing of textiles are estimated to be released into the ocean on anannual basis. Certain high surface area microfibers can absorb largetoxin loads and resemble microscopic plankton, thereby ending up bioaccumulated in the food chain by several orders of magnitude. In turn,because humans typically consume top predator species, such microfiberpollution may negatively affect human health.

As additional issues, items such as carpet and upholstery (bothresidential and commercial) are bulky relative to garments, andtypically incorporate larger, bulkier yarns, and thus can occupysignificant landfill space.

In the non-woven context, the now ubiquitous “wipes” of all types(typically a non-woven sheet or several ply sheet) likewise take upsignificant space, and can also have a tendency, even when considered“flushable,” to clog municipal sewage systems, particularly given theincreasing use of low volume, low flow commodes.

In view of these environmental problems, the creation of biodegradablepolymers has been the subject of intense academic and industrialinterest. These include the following examples, which are representativerather than comprehensive.

Shah et al. in “Microbial degradation of aliphatic andaliphatic-aromatic co-polyesters,” Appl. Microbiol. Biotechnol (2014)98:3437-3447 has reviewed the literature concerning the degradation ofthe polyesters and has remarked that “most of the biodegradable plasticsare polyesters with potentially hydrolysable ester bonds, and these aresusceptible to hydrolysis by depolymerases;” and that the aliphaticpolyesters degrade easily as compared to aromatic esters due to theirflexible polymer chain. Some polyesters, such as PET, are notbiodegradable as that term is used in the invention described herein.

Numerous patents have described biodegradable polymeric compositions.For example, in WO 2016/079724 to Rhodia Poliamida polyamidecompositions are modified in order to produce biodegradable polyamidefibers. In this patent, the biodegradation rate is measured according tothe ASTM D5511 testing standard. On pages 8-9, prior art approaches tobiodegradation are discussed including: photo-degradation, prodegradantadditives such as transition metal salts, and biodegradable polymersthat rapidly degrade leaving behind a porous structure having a highinterfacial area and low structural strength; these biodegradablepolymers 10 are listed as including starch-based polymers, polylacticacid, polycaprolactone, polybutylene succinate, polybutyleneterephthalate-coadipate, and several others; however, the patentapplication states that “unfortunately, higher amounts are required torender the polymer biodegradable, compatibilizing and plasticizingadditives are also needed.” As exemplary biodegradation agents, thispatent refers to US Published Patent Application No. 2008/0103232 15 toLake et al. The biodegradation agent is advantageously a masterbatchincluding at least six additives: (1) chemo attractant or chemo taxiscompound; (2) glutaric acid; (3) carboxylic acid with a chain length offrom 5-18 carbons; (4) biodegradable polymer; (5) carrier resin; and (6)swelling agent. The inventive example made polyamide fiber bymelt-spinning using 2% of masterbatch of the commercially availablebiodegradation agent Eco-One®. The resulting fibers were tested via theASTM D5511 standard and were found to degrade 13.9% or 15.5% after 300days. The fibers without biodegradation agent degraded 2.2 and 2.3%under the same ASTM D5511 testing.

LaPray et al. in US 2018/0100060 produce biodegradable articles such asa film, bag, bottle, cap, sheet, box or other container, plate or thelike that are made from a blend of a polymer with a carbohydrate-basedpolymer. The biodegradability is tested according to establishedstandards such as ASTM D-5511 and ASTM D-6691 (simulated marineconditions).

Tokiwa et al. describe biodegradable resin compositions comprising abiodegradable resin and a mannan (polysaccharide) digestion product.Tokiwa et al. list biodegradable mannan digestion products includevarious mannooligosaccharrides.

Bastioli et al. in U.S. Pat. No. 30 8,466,237 describes a biodegradablealiphatic-aromatic copolyester made from 51 to 37% of an aliphatic acidcomprising at least 50% brassylic acid (1,11-undecanedicarboxylic acid)and 49 to 63% of an aromatic carboxylic acid. The biodegradable polymercan be additionally modified by the addition of starch or polybutylenesuccinate and copolymerization with lactic acid or polycaprolactone.

Lake et al. in U.S. Pat. No. 9,382,416 describe a biodegradable additivefor polymeric material comprising a chemo attractant compound, aglutaric acid, a 5 carboxylic acid, and a swelling agent. Furanonecompounds are discussed as attractants for bacteria.

Wnuk et al. in U.S. Pat. No. 5,939,467 describes a biodegradablepolyhydroxyalkanoate polymer containing a second biodegradable polymersuch as polycaprolactone with examples of cast and blown films.

A variety of biodegradable formulations are known, typically outside thefield of textiles that do not address the issue of launderability, someof which may utilize calcium carbonate. For example, Yoshikawa et al. inUS Published Patent Application No. 2013/0288322, Jeong et al. inWO/2005/017015, Tashiro et al. in U.S. Pat. No. 9,617,462, andWhitehouse, in US Patent Application 2007/0259584.

Despite these intensive efforts, there remains a need for novel methodsand materials that provide synthetic textiles that are durable andwater-resistant but that degrade in waste water treatment anaerobicdigesters, landfill conditions and marine environments. Thus, it wouldbe beneficial to create synthetic textiles that maintain their desirableproperties but that also degrade more rapidly than conventionalsynthetic textile materials during waste water treatment, in anaerobicdigesters, in landfill conditions, and in marine environments.

SUMMARY OF THE INVENTION

In one aspect, the invention provides a masterbatch, comprising: 0.2 to5 mass % CaCO₃; an aliphatic polyester comprising a repeat unit havingfrom two to six carbons in the chain between ester groups, wherein the 2to 6 carbon chain repeat unit does not include side chain carbons; and acarrier polymer comprising PET, nylon, olefins, other thermoplasticpolymers, and combinations thereof. The 2 to 6 carbons in chain repeatunit do not include carbons in the ester (COOR) moiety and if side-chaincarbons are present there could be more than 6 carbons (plus estercarbon) in a repeating group.

In some preferred embodiments of any of the inventive aspects, thealiphatic polyester comprises a repeat unit having from three to sixcarbons, or from 2 to 4 carbons, in the chain between ester groups. Inparticularly preferred embodiments the aliphatic polyester comprisespolycaprolactone. In some preferred embodiments, the masterbatch furthercomprises polybutylene succinate (PBS), polybutylene succinate adipate(PBSA), polylactic acid (PLA), polyethersulfone (PES),polyhydroxybutyrate (PHB), poly(3-hydroxybutyrate-co-3-hydroxyvalerate)(PHBV), polybutylene adipate terephthalate (PBAT), polybutylenesuccinate adipate (PBSA), poly(butylenes succinate-co-terephthalate)(PBST), poly(butylene succinate/terephthalatehsophthalate)-co-(lactate)PBSTIL, and combinations thereof.

Preferably, the masterbatch (and the textile) comprises essentially nosaccharides.

In another aspect, the invention provides a molten intermediate,comprising: an aliphatic polyester, other than PET, comprising a repeatunit having from two to six carbons in the chain between ester groups,wherein the 2 to 6 carbon chain repeat unit does not include side chaincarbons; 0.01 to 0.2 mass % CaCO₃; and at least 90 mass % PET, nylon,olefins, other thermoplastic polymers, and combinations thereof. As usedherein, the phrase “other than PET” can be expressed as “other thanpolyethylene terephthalate,” or “with the proviso that the aliphaticpolyester is not polyethylene terephthalate.”

In a further aspect, the invention provides a fiber comprising: analiphatic polyester, other than PET, comprising a repeat unit havingfrom two to six carbons in the chain between ester groups, wherein the 2to 6 carbon chain repeat unit does not include side chain carbons; 0.01to 0.2 mass % CaCO₃; and at least 90 mass % PET, nylon, olefins, otherthermoplastic polymers, and combinations thereof.

In various embodiments, the textile may have one or any combination ofthe following properties: biodegradability such that, when subjected tothe conditions of ASTM D5511 for 266 days, the textile decomposes atleast 40%, or at least 50%, or in the range of 40% to about 80%, or arange of 40% to about 75%; wherein the decomposition products from theASTM testing are primarily methane and carbon dioxide; a dimensionalstability such that the textile maintains its shape and shrinks by lessthan 10%, or less than 5%, or less than 3%, when subjected to theconditions of Home Laundering Test AATCC 135-2015 1IIAii (machine washat 80° F., tumble dry, five laundering cycles); wherein the textile iscolored and possesses a colorfastness of at least Grade 3, or at leastGrade 4, or Grade 5 when subjected to the conditions of AATCC 61-2013 2A(mod 105° F.) or AATCC 8-2016, or AATCC 16.3-2014 (Option 3, 20 AFU); abursting strength of at least 20 psi, preferably at least 50 psi, or atleast 100 psi, or in the range of 50 to about 200 psi, or 50 to about150 psi, when subjected to the conditions of ASTM D3786/D3886M-13; and awicking ability such that when subjected to the conditions of AATCC197-2013; Option B, the textile wicks water over a distance of at least10 mm or at least 20 mm, or in the range of about 10 or about 20 mm toabout 150 mm in 2 minutes.

In yet another aspect, the invention provides a method of making fibers,yarn, or fabric comprising: blending the masterbatch described hereininto a polymer comprising: PET, nylon, olefins, other thermoplasticpolymers, and combinations thereof to form a molten mixture; extrudingthe mixture to form filaments; and cooling the filaments. Thesefilaments can be textured and knitted (“filament yarn”), formed intononwoven webs, or cut into staple for woven, nonwoven and knitted fabricapplications. Alternatively, the molten mixture can be extruded to formpellets, and the pellets can be subsequently remelted prior to the stepof extruding the mixture to form fibers. In a further aspect, theinvention provides a textile, comprising: a fiber comprising CaCO₃ andat least 90 mass % PET, nylon, olefins, other thermoplastic polymers,and combinations thereof; and possessing biodegradability such that,when subjected to the conditions of ASTM D5511 for 266 days, the textiledecomposes at least 40%, or at least 50%, or in the range of 40% toabout 80%, or a range of 40% to about 75%; and wherein the textilecomprises one or more of the following properties: a dimensionalstability such that the textile maintains its shape and shrinks by lessthan 10%, or less than 5%, or less than 3%, when subjected to theconditions of Home Laundering Test 5 AATCC 135-2015 1IIAii (machine washat 80F, tumble dry, five laundering cycles); wherein the textile iscolored and possesses a colorfastness of at least Grade 3, or at leastGrade 4, or Grade 5 when subjected to the conditions of AATCC 61-2013 2A(mod 105 F) or AATCC 8-2016, or AATCC 16.3-2014 (Option 3, 20 AFU); abursting strength of at least 20 psi, preferably at least 50 psi, or atleast 100 psi, or in the range of 50 to about 200 psi, or 50 to about150 psi, when subjected to the conditions of ASTM D3786/D3886M-13; andwicking ability such that when subjected to the conditions of AATCC197-2013, Option B, the textile wicks water over a distance of at least10 mm or at least 20 mm, or in the range of about 10 or about 20 mm toabout 150 mm in 2 minutes.

Advantages of the invention may include, in some preferred embodiments,enhanced biodegradability per mass % of a masterbatch; greaterdurability of the fiber or textile as compared to other biodegradabilitytreatments; better maintenance of fiber or textile properties.

The foregoing and other objects and advantages of the invention and themanner in which the same are accomplished will become clearer based onthe followed detailed description taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1-5 are plots of percentage (%) biodegradation versus elapsed time(expressed in days) for several embodiments of the present inventionalong with control examples of cellulosic materials and conventionalpolymers.

FIG. 6 is an SEM micrograph of partially digested fibers according tothe invention.

FIG. 7 is a series of photographs illustrating plant testing of theinvention.

DETAILED DESCRIPTION OF THE INVENTION Glossary

An “aliphatic polyester” contains repeating ester units with hydrocarbonchains comprising open (not aromatic) chains. These may be homopolymers,copolymers containing only aliphatic groups, or copolymers containingboth aliphatic groups and aryl groups.

A “carrier polymer” is a polymer in the masterbatch that is the same as,or is compatible and miscible with, the polymer into which themasterbatch is blended.

Denier (Dpf) is the weight in grams of 9,000 meters of the individualfilament. It can be calculated by taking the yarn denier and dividing itby the number of filaments in the yarn bundle.

For purposes of the present invention, a non-biodegradable polymer isone that degrades by 10% or less after 266 days of testing according toASTM D-5511.

PET, nylon, and spandex have the conventional meaning Nylon is apolyamide; one preferred nylon is nylon 6,6. Spandex is apolyether-polyurea copolymer.

Polymers are large molecules (molecular weight over 100 Daltons,typically thousands of Daltons) comprising many repeating units.

A textile is a type of material composed of natural and/or synthetic 5fibers, filaments or yarn, and may be in knit, woven or non-woven forms.

The term “nonwoven fabric” is well understood by the person of ordinaryskill in this art, and is used herein consistent with such understandingincluding definitions such as those in Tortora, Phyllis G., and RobertS. Merkel. Fairchild's Dictionary of Textiles. 7th ed. New York, N.Y.:Fairchild Publications, 2009, page 387.

Thus, a nonwoven fabric is, “a textile structure produced by bonding orinterlocking of fibers, or both; accomplished by mechanical, chemical,thermal, or solvent means and combinations thereof.” Exemplary methodsof forming the basic web include carding fibers, air laying, and wetforming. These webs can be secured or bonded by use of adhesives,including low-melt fibers interspersed among the web, thermal bondingfor appropriate thermoplastic polymers, needle punching, spunlace(hydroentanglement), and spun bonded processes.

The skilled person understands that in the textile arts, the word“spinning” has two different definitions, both of which are clear incontext. In forming synthetic filament, the term “spinning” refers tothe step of extruding the molten polymer into filament.

In the context of natural fibers, or staple fibers cut from texturedsynthetic filament, the term “spinning” is used in its most historicalsense (dating to antiquity) of twisting filaments into a cohesive yarnstructure from which fabrics can be woven.

As a general reference, Phyllis G. Tortora and Robert S. Merkel,Fairchild's Dictionary of Textiles 7th Edition, New York, FairchildPublications 2009, provides many other definitions recognized by thoseof ordinary skill in this art (skilled persons).

ASTM and AATCC testing protocols are considered industry standards.These protocols typically do not change significantly over time;however, if any question arises regarding the dates of these standards,not specified herein, the standard in effect on January 2018 is to beselected.

Unless defined to the contrary, the term “percentage” or the symbol “%”refers to mass percentage (“mass %”), which carries the same meaning inthis specification as “weight percentage” or “percent by weight.” Theseusages are well understood in context by the skilled person.

The masterbatch formulation that enables bio-degradation typicallycomprises a carrier polymer. The carrier polymer is preferablyformulated to match the matrix (i.e., the nonbiodegradable polymer).Thus, in exemplary embodiments the carrier polymer is selected from thegroup consisting of PET, nylon, olefins, other thermoplastic polymers,and combinations thereof. As demonstrated by the examples, PET andnylon, in combination with other components of the invention, have beenshown to result in superior biodegradability in a launderable textile.

Surprisingly, the inventors have discovered that the addition of calciumcarbonate in the masterbatch substantially increases thebiodegradability of the resulting textiles while avoiding negativeeffects on launderability.

Although the invention is not limited by the mechanism by which calciumcarbonate operates, and although the inventors do not wish to be boundby any particular theory, the following hypothesis appears reasonable.The presence of microscopic inorganic particles of calcium carbonatemixed in a homogenous organic polymeric matrix introduces a plethora ofnucleation points for biodegradation. This calcium carbonate is dosedsimultaneously with other biodegradable ingredients, rendering thenucleation points to be in close proximity with these ingredients.Calcium ions may play an important role in bacterial growth. Calciumbinding proteins present in bacteria help in signal transduction, andmay assist in the important process of positive chemotaxis where thebacteria move towards higher concentrations of a chemical.

According to this hypothesis, the breakdown of the polymer into monomersand oligomers by hydrolysis of the ester linkages by the action ofanaerobic bacteria are accelerated by the presence of dispersed calciumcarbonate. The presence of carbon dioxide, a metabolic byproduct, canalso enhance the dissolution of calcium carbonate present in the polymermatrix.

Another mechanism where calcium and calcium binding proteins in bacteriacan play an important role is in quorum sensing; i.e., a means ofcommunication in bacteria optimized for population growth. Theindividual bacteria work to create a hydrogel, composed of bacteria andextra cellular polymeric materials that create a coordinated functionalcommunity. This macroscopic structure magnifies the bacterial action andhelps lead to the biodegradation of polymers according to the invention,especially high surface area microfibers that can be incorporated intosuch a hydrogel.

The masterbatch formulation is embedded within the polymer matrix. As afurther aspect of the hypothesis, the chemical part of the hydrolyticattack on the polymer chains begins from within. The masterbatchdispersed within the matrix creates nucleation points for attack andexponentially multiplies the fiber surface area. The bacterial enzymesattack from the outside working their way in. Bacteria, being in the 1micron range, will initially work on the textile fibers from theoutside, but as the polymer matrix solvates and breaks down, new surfacearea is exposed. With the formation of a coordinated bacterial communityin the hydrogel, large polymeric chains are broken down to oligomericchains and further broken into monomers and digested into CO₂ and CH₄.

As a result, the masterbatch of the invention can be thought of actingin two phases: physiochemical at the beginning to break down to smallerbits and biochemical in the latter half to digest the 25 material.

In some embodiments, the fibers in the yarns or textiles have a denierper filament (dpf) in the range of 1 to 50 or 2 to 30, or as high as1,000. The denier of the fibers is not believed to be critical in thebiodegradability because the fibrous textiles will generally havesufficient surface area to support bacterial growth.

In exemplary embodiments, the masterbatch comprises at least 0.5 mass %calcium carbonate, in some embodiments up to 10% calcium carbonate, insome cases between about 0.5 and 5% calcium carbonate, and typically atleast about 1.0% calcium carbonate. The inventive compositionspreferably use fine calcium carbonate powders, preferably having a massaverage particle size of 15 microns (μm) or less, 10 μm or less, in someembodiments 7 μm or less, and may be in the range of a mass averageparticle size of between 0.1 and 10 μm, or between 1 and 8 μm, orbetween 5 and 8 μm. As is conventional, particle size can be measured bycommercial photoanalysis equipment or other conventional means. Thecalcium carbonate powder has a surface area of at least 0.5 squaremeters per gram (m²/g); in some cases at least 1.0 m²/g and in someembodiments between 0.5 and 10 m²/g. As is conventional, surface areacan be determined by a method such as the ISO 9277 standard forcalculating the specific surface area of solids which in turn is basedon the Brunauer-Emmett-Teller (BET) theory.

In some preferred embodiments, the masterbatch formulation contains oneor any combination of the following: polycaprolactone (PCL),polyhydroxybutyrate (PHB), polybutylene succinate (PBS), polylactic acid(PLA), and poly(tetramethylene adipate-coterephthlate).Polycaprolactone, or blends comprising PCL as the major aliphaticpolyester component appear favorable because, surprisingly, PCL wasfound to outperform polylactic acid (PLA), PHB and PBS.

Because textiles need to be durable, the masterbatch and textilecompositions should avoid components that adversely affect durability.Preferably, the compositions have less than 5 mass %, more preferablyless than 2%, or less than 1% of saccharides; or less than these amountsof furanones; or less than these amounts of organic (carbon-based)components that leach out during laundering. In some embodiments, theinventive compositions lack any components that substantially diminishlaundering durability.

The textiles preferably have a dimensional stability such that thetextile maintains its shape and shrinks by less than 10%, or less than5%, or less than 3%, as measured by Home Laundering Test AATCC 135-20151IIAii (machine wash at 80 F, tumble dry, five laundering cycles).

The textiles or fibers may be colored (such as red, blue, green, etc.)and preferably possess a colorfastness of at least Grade 3, or at leastGrade 4, or Grade 5 as measured by AATCC 61-2013 2A (mod 105 F) or AATCC8-2016, or AATCC 16.3-2014 (Option 3, 20 AFU). A sheet of the textile(for example a fabric sample cut from a shirt or pants) preferably has abursting strength of at least 20 psi, preferably at least 50 psi, or atleast 100 psi, or in the range of 50 to about 200 psi, or 50 to about150 psi, where bursting strength is measured 30 according to ASTMD3786/D3886M-13.

In some preferred embodiments, the fabrics have no piling or fuzziness(Grade 5 according to ASTM D 3512M-16).

In some embodiments, the textile wicks water; this is especiallydesirable in clothing in which sweat is wicked away from the wearer; insome preferred embodiments the fabric wicks water over a distance of atleast 10 mm or at least 20 mm, or in the range of about 10 or about 20mm to about 150 mm in 2 minutes; as measured by AATCC 197-2013.Measurements of textiles made according to some embodiments of theinvention are shown in the performance testing comparison tables (i.e.,Tables 1-7).

In some cases, the precise chemical structure within the fibers may notbe known and one, or a combination, of the properties discussed above isthe most accurate and/or precise way to characterize the textile. Themasterbatch is blended with a non-biodegradable polymer such aspolyethylene terephthalate, nylon, olefins, other thermoplasticpolymers, and combinations thereof. For purposes of the presentinvention, a non-biodegradable polymer is one that degrades by 10% orless (preferably 5% or less, in some embodiments, 3% or less, and insome embodiments between 2 and 10% or 2 and 5%) after 266 days oftesting according to ASTM D-5511 when the polymer does not contain theadditives (in other words, prior to blending with the masterbatch). Thefiber comprises at least 50 mass %, more preferably at least 70%, stillmore preferably at least 90%, or at least 95%, and in some embodimentsat least 99% of a polymer selected from the group consisting ofpolyethylene terephthalate (PET), nylon, olefins, other thermoplasticpolymers, and combinations thereof.

The invention includes textiles comprising these fibers, either assingle component textiles or in mixtures with other fibers. Manytextiles comprise mixtures (blends) of fibers, for example, textilescontaining spandex often include cotton fibers. In some embodiments, thetextiles include at least 10%, or at least 20%, or at least 50%, or atleast 80%, or at least 90%, or 100% of the fibers made from polyethyleneterephthalate (PET), nylon, olefins, other thermoplastic polymers, andcombinations thereof.

Fibers produced from the masterbatch typically include at least 90 mass% of a non-biodegradeable polymer. Because the masterbatch is preferablyadded in an amount between 0.5 to 5%, preferably at least 1%, in someembodiments between 1 and 5%, in some embodiments between 2 and 5%, andbecause all of the masterbatch is present in the resulting composition,the resulting fibers will contain the corresponding amounts ofmaterials.

The invention also includes blended intermediates, fibers, yarns andtextiles. Examples of finished products according to the presentinvention include: knit fabrics, woven fabrics, nonwoven fabrics,apparel, upholstery, carpeting, bedding such as sheets or pillowcases,industrial use fabrics for agriculture or construction. Examples ofapparel include: shirts, pants, bras, panties, hats undergarments,coats, skirts, dresses, tights, stretch pants, and scarves.

The calcium carbonate particles are, of course milled to a size usefulfor the invention. Expressed functionally, the milled particles can beas small as possible, and very small particles present no disadvantage.

An upper limit of particle size is, however, defined in part by thedenier, which the lay person would describe in terms of diameter. Inthose terms, the average calcium carbonate particle size should be nolarger than 10% of the diameter of the extruded filament, and themaximum particle size should be no greater than 20% of the diameter ofthe extruded filament, because particle sizes greater than about 10% offilament diameter are much more likely to lead to breakage at all phasesof production and use.

As noted above, the lower limit is less critical, with the mainconsideration being the increased difficulty and cost of producing eversmaller particles.

Thus, as a practical example a one denier (1 D) polyester fiber has adiameter of 10 microns (μ), meaning that the calcium carbonate particlesize should not exceed about 1μ. Skilled persons will be able to selectrelevant particle sizes based on this general 10% relationship.

In a similar relationship, the masterbatch composition can be producedin solid chip form for storage and transportation. The end user can thenmill the chip into the desired sizes for their particular end useapplications.

In some embodiments, the milled masterbatch particles are then mixedwith a liquid which will in turn be miscible with the desired endpolymer. As an example (but not a limitation), polyethylene glycol orethyl alcohol are suitable for polyester processes.

As further considerations, the prepared masterbatch can be added to thetarget polymer at alternative stages of production. As one option, themasterbatch can be added to a polymer production line after the polymerhas been made, but while the polymer remains in the molten state.

Alternatively, the masterbatch can be added to a continuous polymer lineduring polymerization of the target polymer. In such arrangements, themasterbatch works well if miscible with the last stage ofpolymerization, for example, in the high polymerizer of a continuousline.

Spandex. In the context of the invention, spandex can be the targetpolymer for the masterbatch process provided that the spandex is meltspinnable. The skilled person recognizes that variations of spandex aresolvent-spun rather than melt-spun, and the invention is used with themelt-spun versions.

Examples throughout this description are not intended to be limiting,but, in various embodiments, the invention can be characterized by anyselected combination of features. In some embodiments, the compositionscan be defined, in part, by the absence of certain components. In someembodiments, the compositions avoid including starch or saccharides;such components can be excessively soluble and lead to textiles thatlack sufficient durability. The additives such as polybutylene succinatepreferably do not copolymerize with the non-biodegradable polymer butform degradable phases within the compositions.

In some embodiments, the compositions of the invention avoid aliphaticaromatic polyesters.

The inventive fibers, yarns, and fabrics can be characterized by theirphysical properties such as by the ASTM and/or AATCC tests described inthe Examples. For instance, the fibers, yarns, and fabrics can bedefined by the extent of degradation according to an ASTM test on abasis of mass % biodegradation agent in the fiber. The molecularcomposition of the precursors, intermediates and final products can bedetermined by conventional methods such as gel permeationchromatography, more preferably gradient analysis of polymer blends.

The skilled person will understand, of course, that once the masterbatch is used in conjunction with the main polymer, the compositionalnumbers will change in proportion to the relative amount of masterbatchadded to main polymer.

The skilled person will also understand that when the invention isconsidered in its embodiment as a molten intermediate, the melt can beextruded in the form of either pallets or filament in the most commontextile applications. Extruding and quenching the melt as pelletsprovides the opportunity to store, ship, and re-melt the pellets at adifferent location; e.g. at a customer's location.

When quenched filaments from the composition can be textured usingtechniques well understood by the skilled person, following which fabriccan be formed directly from the textured filament (“filament yarn”), orthe textured filament can be cut into staple fiber. Such staple fibercan in turn be spun into a yarn, most commonly in an open-end system,but obviously ring-spinning as well. The yarn can in turn be formed intofabrics (woven, knitted, nonwoven) or can be blended with anotherpolymer (e.g., rayon), or with natural fiber (cotton or wool) to form ablended yarn which in turn can be made into fabrics having thecharacteristic of the blended fibers.

Any recipe from table 1 can be used in any of the filament, pellet,staple fiber, textured staple fiber, textured filament, or fabricsreferred to herein.

As used herein the term “nap” as well as “napping” or “napped” refer tothe well-understood finishing step for manufactured textiles e.g.,Tortora, supra at pages 378-79. In this context, the invention is alsouseful in polar fleece; i.e. the soft napped insulating fabric typicallymade from polyester.

When formed into appropriate filament, the compositions according to theinvention are expected to work very well as the filling for insulatedgarments.

The nature, structure, and many variations of insulated garments arewell understood to the skilled person. Basically, an insulating materialis enclosed in a lightweight shell, for which low denier nylon istypical, often including a water repellent treatment that can withstandat least some precipitation.

Down is of course the best insulating material based onweight-for-weight compressibility, loft, and warmth-to-weight ratio, butsynthetic fillers such as the present invention offer lower cost, andbetter insulating properties when wet, even though slightly heavier andslightly less compressible.

As another example, filaments, fibers and yarns according to theinvention are expected to perform very well as a biodegradable carpet,or portions of such carpets. As well understood by the skilled person, acarpet is a textile floor covering typically formed of pile yarns ortufting yarns attached to a backing. Prior to the advent of syntheticmaterials, and still used currently, typical pile was made from wool andthe backing was made of a woven fabric into which the yarn could bewoven, tufted or otherwise attached.

The skilled person typically uses the terms “carpet” and “rug”interchangeably although in some context a “carpet” covers an entireroom (“wall-to-wall carpeting”) and a “rug” covers an area smaller thana full room.

Because synthetic material such as nylon, polypropylene, polyester, andblends of these with wool are useful carpet materials, fibers or yarnsformed from the invention are entirely appropriate and useful forcarpeting. The skilled person recognizes a wide variety of backingmaterials, backing structures, and means of attaching pile or tuft tothe backing Repeating all such possibilities would be redundant ratherthan clarifying and the skilled person can adopt the necessary materialsand steps in any given context and without undue experimentation.

Examples

A variety of masterbatch compositions were prepared having thecompositions shown in Table 1.

TABLE 1 Recipe # 2 3 4 5 6 7 8 9 10 11 12 13 14 PET 40 40 40 40 40 40 4040 40 40 40 40 39 PCL 49 49 49 49 49 39 49 39 39 39 49 39 39 PLA 10 0 00 0 0 0 10 0 0 5 0 0 P3HB (PHA) 0 10 0 5 0 0 0 0 10 10 0 10 10PBS-version 1 0 0 0 0 10 0 0 0 0 0 0 0 0 PBS-version 2 0 0 10 0 0 20 0 00 10 0 10 10 CaCO₂ 1 1 1 1 1 1 1 1 1 1 1 0 1 PBAT 0 0 0 5 0 0 10 10 10 05 0 0 SiO₂ 0 0 0 0 0 0 0 0 0 0 0 1 1 Total (in %) 100 100 100 100 100100 100 100 100 100 100 100 100

These masterbatches were blended into polyethylene terephthalate (1% ofmasterbatch is typical) and fed with a gravimetric feeder in a closedloop to the melt extruder fitted with twin screws. The additive batch ismixed at 250° C. and extruded via a strand die into a water bath orequivalent quenching equipment. After a classifier removes particles atthe extreme ends of the pellets' size distribution, the pellets aredried and bagged.

The calcium carbonate utilized in the testing had a mass averageparticle size of 6.5 microns and a surface area of about 1.5 squaremeters per gram.

The formulations were extruded into PET at a 1% load rate and therecipes that were most compatible with the extrusion process were testedfor degradation according to ASTM D5511. The results are shown in FIG. 1and Table 2 in for 266 days and in FIG. 2 and Table 3 for 353 days.

TABLE 2 266 Day ASTM D5511 Biodegradation Update- Fibers From SelectedRecipes Recipe Recipe Recipe Recipe Recipe Inoculum Negative Positive #2#3 #6 #7 #11 Cumulative Gas Volume (mL) 3567.7 4312.7 11822.8 15922.620920.1 19036.7 9476.7 13849.5 Percent CH₄ (%) 47.2 44.7 42.6 48.2 53.348.4 49.6 51.8 Volume CH₄ (mL) 1682.6 1925.7 5030.9 7680.8 11143.69214.4 4698.8 7176.8 Mass CH₄ (g) 1.20 1.38 3.59 5.49 7.96 6.58 3.365.13 Percent CO₂ (%) 38.8 38.2 41.0 35.4 35.7 37.5 35.7 35.4 Volume CO₂(mL) 1385.1 1648.2 4849.0 5640.3 7461.6 7137.6 3383.4 4907.0 Mass CO₂(g) 2.72 3.24 9.52 11.08 14.66 14.02 6.65 9.64 Sample Mass (g) 1000 1010 20 20 20 20 20 Theoretical Sample Mass (g) 0 8.6 4.2 12.6 12.6 12.612.6 12.6 Biodegraded Mass (g) 1.64 1.96 5.29 7.14 9.97 8.76 4.33 6.47Percent Biodegraded (%) 3.2 86.5 43.6 66.1 56.5 21.3 38.3

TABLE 3 353 Day ASTM D5511 Biodegradation Update-Fibers From SelectedRecipes Recipe Recipe Recipe Recipe Recipe Inoculum Negative Positive #2#3 #6 #7 #11 Cumulative Gas Volume (mL) 3567.7 4397.5 11886.0 16868.922359.2 19793.3 10703.0 15057.3 Percent CH₄ (%) 47.2 44.9 42.6 48.6 53.448.6 50.2 52.1 Volume CH₄ (mL) 1682.6 1975.8 5068.1 8197.3 11943.19622.8 5368.6 7176.87840.4 Mass CH₄ (g) 1.2 1.41 3.62 5.86 8.53 6.873.83 5.60 Percent CO₂ (%) 38.8 38.2 41.0 35.3 35.6 37.3 35.4 35.3 VolumeCO₂ (mL) 1385.1 1678.5 4871.0 5955.1 7968.3 7380.2 3792.4 5317.5 MassCO₂ (g) 2.72 3.30 9.57 11.70 15.65 14.50 7.45 10.45 Sample Mass (g) 100010 10 20 20 20 20 20 Theoretical Sample Mass (g) 0 8.6 4.2 12.6 12.612.6 12.6 12.6 Biodegraded Mass (g) 1.64 1.96 5.32 7.58 10.67 9.11 4.917.05 Percent Biodegraded (%) 3.7 87.2 47.1 71.6 59.2 25.9 42.9

Initial readings were taken at 59 days; at this very early reading itappeared that recipe 13 (Table 1) showed 3.9% degradation while recipe14 did not appear to have started to degrade at all. Based upon abarometric event and noise in the data, however, it appears that thedata from recipes 13 and 14 is unreliable and unreproducible.Additionally, such a low degradation reading is too close to baseline tobe relied upon (3% degradation for the PET without additive) and testingof these recipes was stopped.

The results shown above demonstrate superiority over the prior art. Inthese landfill conditions, the PET fibers degrade to methane and carbondioxide. After 266 days, the PET samples made with 1 mass % of themasterbatch recipes #2, 3, 6, 7, and 11 in the Table degraded 43.6,66.1, 56.5, 21.3, and 38.3%, respectively. The unmodified PET degraded3.2% under the same conditions. The highest degradation occurred from amasterbatch containing 49% polycaprolactone and 10% polyhydroxybutyrate,while the lowest degradation occurred from a masterbatch containing 39%polycaprolactone and 20% polybutylene succinate. The material made from49% polycaprolactone and 10% polyhydroxybutyrate also degradedsubstantially better than the PET modified with 1% of a masterbatchcontaining 39% polycaprolactone, 10% polyhydroxybutyrate and 10%polybutylene succinate.

The results above can be compared with the results reported in WO2016/079724 (“Table 1—Results after 300 days”) in which polyamide fiberswere melt-spun using 2% of masterbatch of the commercially availablebiodegradation agent Eco-One®(https://ecologic-llc.com/about/eco-one-video-tour; accessed Feb. 11,2019). The resulting fibers were tested via the ASTM D5511 standard andwere found to degrade 13.9% (“PA 6.6”) or 15.5% (“PA 5.6”) after 300days. The WO 2016/079724 fibers without biodegradation agent degraded2.2 and 2.3% under the same ASTM D5511 testing.

Based on the unmodified fibers, and ignoring the difference between 266and 300 days, conventional PET (Table 2 herein) appears to be3.2/2.25=1.42× more degradable than the polyamide fibers in WO2016/079724. In comparison, the modified PET according to the invention,was between 21.3/15.5=1.37× and 66.1/15.5=4.26× more degradable than themodified polyamide fibers in WO 2016/079724. Correcting for the factthat the polyamide fibers in WO 2016/079724 were modified by twice asmuch masterbatch (2% versus 1%), the PET according to the invention wasbetween 2.74× and 8.52× more degradable. Correcting for the 2.74/1.42difference between the unmodified polyester and polyimide, the presentinvention demonstrated between 1.92× and 3.00× greater biodegradability.

Table 4 and FIG. 3 show the improvement in the biodegradation of fabricsmade from Recipe 2 (Table 1) and a control polyester.

TABLE 4 112 Day ASTM D5511 Biodegradation Update Fabrics from a SelectedRecipe and a Control Fabric from Fabric from PET conventional InoculumNegative Positive w/Recipe #2 PET Cumulative Gas 1420.6 1588.7 10124.65480.3 1753.7 Volume (mL) Percent CH₄ (%) 24.0 28.9 39.7 43.5 41.6Volume CH₄ (mL) 340.8 459.3 4024.5 2384.0 729.5 Mass CH₄ (g) 0.24 0.332.87 1.70 0.52 Percent CO₂ (%) 48.8 41.9 42.1 38.5 40.0 Volume CO₂ (mL)692.7 665.5 4261.7 2109.6 701.1 Mass CO₂ (g) 1.36 1.31 8.37 4.14 1.38Sample Mass (g) 10 10 10 20 20 Theoretical 0 8.6 4.2 12.4 12.4 SampleMass (g) Biodegraded 0.55 0.60 4.44 2.41 0.77 Mass (g) Percent 0.6 92.115.0 1.7 Biodegraded (%)

ASTM D5210—Anaerobic Degradation in the Presence of Sewage Sludge

The finished fabrics from two formulations were stone tumbled to createmicrofibers and the microfibers were tested for degradation according toASTM D5210 for 55 days which models the conditions typically experiencedin a water treatment facility. The results are shown in Table 5 and FIG.4.

TABLE 5 55 Day ASTM D5210 Biodegradation Update Microfibers fromSelected Recipes PET PET PET PET Microfibers Microfibers MicrofibersMicrofibers Inoculum Negative Positive Untreated Recipe #2 Recipe #6Recipe #3 Cumulative Gas Volume (mL) 377.9 274.6 5515.8 397.9 3268.42895.2 3160.5 Percent CH₄ (%) 49.8 45.3 53.6 47.0 42.0 41.2 43.3 VolumeCH₄ (mL) 188.2 124.5 2958.2 186.9 1372.6 1194.1 1368.3 Mass CH₄ (g) 0.130.09 2.11 0.13 0.98 0.85 0.98 Percent CO₂ (%) 37.9 38.4 37.3 42.2 41.841.0 38.8 Volume CO₂ (mL) 143.1 105.5 2055.9 167.8 1365.3 1188.3 1226.7Mass CO₂ (g) 0.28 0.21 4.04 0.33 2.68 2.33 2.41 Sample Mass (g) 10 10 1020 20 20 20 Theoretical Sample Mass (g) 0 8.6 4.2 12.4 12.4 12.4 12.4Biodegraded Mass (g) 0.18 0.12 2.69 0.19 1.47 1.28 1.39 PercentBiodegraded (%) −0.6 59.4 0.1 10.4 8.9 9.8

ASTM D6691—Aerobic Degradation Modeling 5 a Marine Environment

The finished fabric from one formulation was stone tumbled to createmicrofibers and the microfibers were tested for degradation according toASTM D6691 for 112 days. The results are summarized in Table 6 and FIG.5.

TABLE 6 112 Day ASTM D6691 Biodegradation Update Microfibers From aSelected Recipe and a PET Control PET PET Microfibers MicrofibersInoculum Negative Positive Untreated Recipe #6 Cumulative Gas 9.93 8.6386.55 16.17 39.5 Volume (mL) Percent CO₂ (%) 75.23 74.22 80.94 70.5077.0 Volume CO₂ (mL) 7.47 6.41 70.06 11.40 30.4 Mass CO₂ (g) 0.015 0.0130.138 0.022 0.060 Sample Mass (g) 1000 0.1 0.1 0.1 0.10 Theoretical 00.09 0.04 0.07 0.07 Sample Mass (g) Biodegraded 0.004 0.003 0.038 0.0060.016 Mass (g) Percent −0.66 79.45 2.81 16.9 Biodegraded (%)

Example—Nontoxicity

A composition was tested using the ASTM E1963 method, a protocol toconduct plant toxicity tests using terrestrial plant species such asbean, corn and peas to determine effects of test substances on plantgrowth and development. The peas are a good indicator, because they arevery sensitive to soil conditions. The leachate of residual soilcontaining the byproducts from ASTM D5511 testing from Recipe 2 wereused in this ASTM E 1963 test. FIG. 7 shows the results from the ASTM E1963 Test.

Inspecting the growth of the plants in the background (1st column) andsample (3rd column), demonstrates that there is no inhibitory effect ofleachate from the relevant byproducts sample on plant growth.

TABLE 7 Examples of Textile Properties With and Without MasterbatchFabric Fabric With Without Test Type Invention Invention Explanation OfTest Results Dimensional changes after home laundering −1.7 −2.7 Bothfabrics have extremely low shrinkage AATCC 135- 2015, 1||Aii rates,percentages +/−3% are considered to be (Machine wash cold normal cycleat 80° +/− 5° excellent results. There is a negative F.; tumble dry low)difference between the invention and After 5 launderings conventionalversions LENGTH (average) Remarks: (+) means extension (−) meansshrinkage Dimensional changes after home laundering −1.3 −0.9 Bothfabrics have extremely low shrinkage AATCC 135- 2015, 1||Aii rates,percentages +/−3% are considered to be (Machine wash cold normal cycleat 80° +/− 5° excellent results. There is a negative F.; tumble dry low)difference between the invention and After 5 launderings conventionalversions WIDTH (average) Remarks: (+) means extension (−) meansshrinkage Colorfastness to accelerated laundering 4.5 4.5 Both fabricswere tested using accelerated AATCC 61-2013 2A mod105° F. laundrymethods with elevated temperatures. COLOR CHANGE General colorchange/colorfastness show Grade 5-negligible or no color change orslight to negligible color change, a 4.5 is staining/color transferconsidered good/excellent according to Grade 4-slight to negligiblecolor change or industry standards. There is no differencestaining/color transfer Grade 3-noticeable between the invention andconventional color change or staining/color transfer versions Grade2-considerable color change or staining/color transfer Grade 1-muchcolor change or staining/color transfer Colorfastness to crocking: 3.53.5 Test specimen is rubbed with DRY white crock Crockmeter method AATCC82016 (as test cloth under controlled conditions. Both received) fabricscolorfastness is within acceptable DRY range, even though some colortransfer is Grade 5-negligible or no color change or noticeable. Thereis no difference between staining/color transfer the invention and theconventional fabric Grade 4-slight to negligible color change orstaining/color transfer Grade 3-noticeable color change orstaining/color transfer Grade 2-considerable color change orstaining/color transfer Grade 1-much color change or staining/colortransfer Colorfastness to crocking: 3.5 4.0 Test specimen is rubbed withWET white crock Crockmeter method AATCC 82016 (as test cloth undercontrolled conditions. Both received) fabrics colorfastness is withinacceptable WET range, even though some color transfer is Grade5-negligible or no color change or noticeable. The difference between a3.5 and staining/color transfer 4 is insignificant Grade 4-slight tonegligible color change or staining/color transfer Grade 3-noticeablecolor change or staining/color transfer Grade 2-considerable colorchange or staining/color transfer Grade 1-much color change orstaining/color transfer Colorfastness to light 4.0 3.0 Both Fabrics weretested using a Xenon light AATCC 16.3-2014; option 3 (20 AFU) source.Colorfastness for the invention is Light source Xenon within anacceptable range, according to most Color change industry standards. Theconventional fabric is Colorfastness key to grade ratings on the lowerend and would typically need to (determined through use of AATCC gray bere-evaluated scales for evaluating color change and staining) Grade5-negligible or no color change or staining/color transfer Grade4-slight to negligible color change or staining/color transfer Grade3-noticeable color change or staining/color transfer Grade2-considerable color change or staining/color transfer Grade 1-muchcolor change or staining/color transfer Bursting strength of textilefabrics 116.4 117 Both fabrics were placed in a hydraulic Diaphragmbursting strength test method diaphragm bursting tester which stretches(hydraulic) fabric to ensure overall strength (i.e., make ASTM Delta3786 Delta 3786 Mike 13 new sure fabric doesn't rip/burst). Both Fabricsline average Papa Sierra India have excellent bursting strengthproperties and are considered strong fabrics. There is a negligibledifference between the invention and the conventional fabrics Pillingresistance and other related surface 5.0 5.0 Using the random tumblepilling tester, both changes of textile Fabrics random tumble fabricpilling resistance results are excellent. pilling ASTM 3512/D 3512M-16.After 30 There is no difference between the invention minutes (average)and the conventional fabric Pilling Key to grade rating 5-no peeling orfuzziness 4-slight pilling or fuzziness 3-moderate peeling or fussiness2-severe peeling or fuzziness 1-very severe peeling or fuzziness Pillingresistance and other related surface 5.0 5.0 Using the random tumblepilling tester, both changes of textile Fabrics random tumble fabricsfuzzing resistance results are excellent pilling ASTM 3512/D 3512M-16.After 30 there is no difference between the invention minutes (average)Fuzzing and the conventional fabric Key to grade rating 5-no peeling orfuzziness 4-slight pilling or fuzziness 3-moderate peeling or fussiness2-severe peeling or fuzziness 1-very severe peeling or fuzziness Stretchproperties of knitted Fabrics having 0.00 0.00 This test method coversthe measurement of low power fabric stretch and fabric growth of knittedASTM D 2594-04 (2012) loose-fitting (comfort fabrics intended forapplications requiring low stretch) after static extension (2 hours) andpower stretch properties. Both fabrics showed relaxation (1 hour) nogrowth percentage in wale direction Wale average (%)growth leading to anexcellent result. There is no difference between the invention and theconventional materials Stretch properties of knitted Fabrics having 100100 This test method covers the measurement of low power fabric stretchand fabric growth of knitted ASTM D 2594-04 (2012) loose-fitting(comfort fabrics intended for applications requiring low stretch) afterstatic extension (2 hours) and power stretch properties. Both fabricsshowed relaxation (1 hour) 100% recovery in wale direction leading to anWale average (%) recovery excellent result. There is no differencebetween the invention and conventional fabrics Stretch properties ofknitted Fabrics having 2.1 1.3 This test method covers the measurementof low power fabric stretch and fabric growth of knitted ASTM D 2594-04(2012) loose-fitting (comfort Fabrics intended for applicationsrequiring low stretch) after static extension (2 hours) and powerstretch properties. Both fabrics relaxation (1 hour) showed very littlegrowth percentage in Course average (%) growth course direction and iswithin an acceptable range. There is a negligible difference between theinvention and conventional Fabrics Stretch properties of knitted Fabricshaving 93.1 95.8 This test method covers the measurement of low powerfabric stretch and fabric growth of knitted ASTM D 2594-04 (2012)loose-fitting (comfort Fabrics intended for applications requiring lowstretch) after static extension (2 hours) and power stretch properties.Both fabrics relaxation (1 hour) showed excellent recovery percentagesin course average (%) recovery course direction and with is within anacceptable range. There is a negligible difference between the inventionand the conventional Fabrics Vertical wicking of textiles 21 20 Thistest method is used to evaluate the ability AATCC 197-2013 option Boriginal state mm mm of vertically aligned fabric specimens to Waterwicking distance in 2 minutes-short 0.17 0.34 transport liquid along airthrough them both period wicking rate mm/s mm/s fabric showed excellentwicking capabilities Lengthwise (average) and is within an acceptablerange. There is a negligible difference between the invention and theconventional fabrics. Vertical wicking of textiles 72 73 This testmethod is used to evaluate the ability AATCC 197-2013 option B originalstate mm mm of vertically aligned fabric specimens to Water wickingdistance in 10 minutes-long 0.12 0.12 transport liquid along air throughthem both period wicking rate mm/s mm/s fabric showed excellent wickingcapabilities Lengthwise (average) and is within an acceptable range.There is a negligible difference between the invention and theconventional fabrics Vertical wicking of textiles 146 146 This testmethod is used to evaluate the ability AATCC 197-2013 option B originalstate mm mm of vertically aligned fabric specimens to Water wickingdistance in 30 minutes-long 0.08 0.08 transport liquid along air throughthem both period wicking rate mm/s mm/s fabric showed excellent wickingcapabilities Lengthwise (average) and is within an acceptable range.There is a negligible difference between the invention and theconventional fabrics. Vertical wicking of textiles 18 17 This testmethod is used to evaluate the ability AATCC 197-2013 option B originalstate mm mm of vertically aligned fabric specimens to Water wickingdistance in 2 minutes-short 0.15 0.29 transport liquid along air throughthem both period wicking rate mm/s mm/s fabric showed excellent wickingcapabilities Widthwise (average) and is within an acceptable range.There is a no difference between the invention and the conventionalfabrics Vertical wicking of textiles 70 69 This test method is used toevaluate the ability AATCC 197-2013 option B original state mm mm ofvertically aligned fabric specimens to Water wicking distance in 10minutes-long 0.12 0.12 transport liquid along air through them bothperiod wicking rate Widthwise (average) mm/s mm/s fabric showedexcellent wicking capabilities and is within an acceptable range. Thereis a negligible difference between the invention and the conventionalfabrics Vertical wicking of textiles 139 139 This test method is used toevaluate the ability AATCC 197-2013 option B original state mm mm ofvertically aligned fabric specimens to Water wicking distance in 30minutes-long 0.08 0.08 transport liquid along air through them bothperiod wicking rate mm/s mm/s fabric showed excellent wickingcapabilities Widthwise (average) and is within an acceptable range.There is a no difference between the invention and the conventionalFabrics

Microscopic Analysis of Fibers Subjected to Bacterial Decomposition

Electron microscopic imaging of fibers subjected to bacterialdecomposition of fibers according to the invention in ASTM D5511 areshown in the SEM image of FIG. 6 (SEM HV: 15 kV; view field 173 microns;SEM magnification 1.5; Tescan™ Vega 3™ tungsten thermionic emission SEMsystem (https://www.tescan.com/en-us/technology/sem/vega3); accessedFeb. 12, 2019), and show bacterial colonization on the surface ofpolyester greige fibers according to the invention, after >1 yearexposure to bacteria.

In the drawings and specification there has been set forth a preferredembodiment of the invention, and although specific terms have beenemployed, they are used in a generic and descriptive sense only and notfor purposes of limitation, the scope of the invention being defined inthe claims.

1. A masterbatch, comprising: 0.2 to 5 mass % CaCO₃; an aliphaticpolyester comprising a repeat unit having from two to six carbons in thechain between ester groups, with the proviso that the 2 to 6 carbons inthe chain do not include side chain carbons; and a carrier polymerselected from the group consisting of PET, nylon, olefins, otherthermoplastic polymers, and combinations thereof.
 2. The masterbatch ofclaim 1 wherein the aliphatic polyester comprises polycaprolactone. 3.The masterbatch of claim 1 further comprising a polymer selected fromthe group consisting of: PBS, PLA, PBSA, PES, PHB, PHBV, PBAT, PBST,PBSTIL, and combinations thereof.
 4. The masterbatch claim 1 wherein thealiphatic polyester comprises a repeat unit having from three to sixcarbons in the chain between ester groups.
 5. The masterbatch of claim 1wherein the aliphatic polyester comprises a repeat unit having four orfive carbons in the chain between ester groups, not including side chaincarbons.
 6. The masterbatch of claim 3 comprising: between 0.9 and 1.1mass percent calcium carbonate; and wherein the 2-6 carbon aliphaticester is polycaprolactone in an amount of 44-54 mass percent; furthercomprising polybutylene succinate in an amount of 9-11 mass percent; andwith the remainder of the masterbatch being polyethylene terephthalateas the carrier polymer.
 7. A polyester composition consistingessentially of 1% by weight (mass) of the master batch of claim 6 andthe remainder polyethylene terephthalate.
 8. The masterbatch accordingto claim 1 consisting essentially of 39-48 weight % polyester; 39-49weight % PLC; and 1 weight % calcium carbonate.
 9. The masterbatchaccording to claim 8 and further comprising a composition selected fromthe group consisting of 5-10% weight PLA, 5-10 weight % PHA, 5-10 weight% PBAT, 10-20 weight % PBS, 1 by weight % silicon dioxide, andcombinations of these compositions
 10. A molten intermediate,comprising: an aliphatic polyester, other than PET, comprising a repeatunit having from two to six carbons in the chain between ester groups,wherein the 2 to 6 carbons in the chain does not include side chaincarbons; 0.01 to 0.2 mass % CaCO₃; and at least 90 mass % of a polymerselected from the group consisting of PET, nylon, and otherthermoplastic polymers, and combinations thereof.
 11. A quenched,size-characterized plurality of polymer pellets formed from the moltenintermediate of claim
 10. 12. A quenched polymer filament formed fromthe molten intermediate of claim
 10. 13. A nonwoven fabric formed fromthe filament of claim
 10. 14. A nonwoven fabric according to claim 13selected from the group consisting of adhesively bonded nonwovenfabrics, thermally bonded nonwoven fabrics, needle punched nonwovenfabrics, hydroentanglement bonded nonwoven fabrics, and spunbondednonwoven fabrics.
 15. A textured filament formed from the quenchedfilament of claim
 12. 16. A fabric formed from the textured filament ofclaim
 15. 17. A cut staple fiber form from the textured filament ofclaim
 15. 18. A yarn form from the staple fiber of claim
 17. 19. Afabric formed from the yarn of claim
 18. 20. A yarn formed from a blendof the staple fiber of claim 17 and cotton.
 21. A fabric formed from theyarn of claim
 20. 22. The molten intermediate of claim 10 consistingessentially of: between 0.9 and 1.1 mass percent calcium carbonate; andwherein the 2-6 carbon aliphatic ester is polycaprolactone in an amountof 44-54 mass percent; further comprising polybutylene succinate in anamount of 9-11 mass percent; and with the remainder of the masterbatchbeing polyethylene terephthalate as the carrier polymer.
 23. The moltenintermediate of claim 22 consisting essentially of: 0.39-0.48 weight %polyester; 0.39-0.49 weight % PLC; and 0.01 weight % calcium carbonate;and at least 90 mass % PET
 24. The molten intermediate of claim 23 andfurther comprising a composition selected from the group consisting of0.05-0.1% weight PLA, 0.05-0.1% PHA, 0.05-0.1% PBAT, 0.10-0.20 weight %PBS, 0.01 by weight % silicon dioxide, and combinations of thesecompositions
 25. A biodegradable fiber comprising: an aliphaticpolyester, other than PET, comprising a repeat unit having from two tosix carbons in the chain between ester groups, wherein the 2 to 6carbons in the chain does not include side chain carbons; 0.01 to 0.2mass % CaCO₃; and at least 90 mass % PET, nylon, olefins, otherthermoplastic polymers, and combinations thereof.
 26. The fiber of claim25 that, when subjected to the conditions of ASTM D5511 for 266 days,decomposes at least 40%, or at least 50%, or in the range of 40 to about80%, or a range of 40 to about 75%.
 27. The fiber of claim 26 whereinthe decomposition products from the ASTM testing are primarily methaneand carbon dioxide.
 28. The fiber of claim 25 characterized by adimensional stability such that the textile maintains its shape andshrinks by less than 10%, or less than 5%, or less than 3%, whensubjected to the conditions of Home Laundering Test 20 AATCC 135-20151IIAii (machine wash at 80 F, tumble dry, five laundering cycles).
 29. Adyed fiber according to claim 25 characterized by a colorfastness of atleast Grade 3, or at least Grade 4, or Grade 5 when subjected to theconditions of AATCC 61-2013 2A (mod 105 F) or AATCC 8-2016, or AATCC16.3-2014 (Option 3, 20 AFU).
 30. The fiber of claim 25 characterized bya bursting strength of at least 20 psi, preferably at least 50 psi, orat least 100 psi, or in the range 25 of 50 to about 200 psi, or 50 toabout 150 psi, when subjected to the conditions of ASTM D3786/D3886M-13.31. The fiber of claim 25 characterized by wicking ability such thatwhen subjected to the conditions of AATCC 197-2013; Option B, thetextile wicks water over a distance of at least 10 mm or at least 20 mm,or in the range of about 10 or about 20 mm to about 150 mm in 2 minutes.32. The fiber of claim 25 consisting essentially of: between 0.9 and 1.1mass percent calcium carbonate; and wherein the 2-6 carbon aliphaticester is polycaprolactone in an amount of 44-54 mass percent; furthercomprising polybutylene succinate in an amount of 9-11 mass percent; andwith the remainder of the masterbatch being polyethylene terephthalateas the carrier polymer.
 33. The fiber of claim 32 consisting essentiallyof: 0.39-0.48 weight % polyester; 0.39-0.49 weight % PLC; and 0.01weight % calcium carbonate; and at least 90 mass % PET.
 34. The fiber ofclaim 33 and further comprising a composition selected from the groupconsisting of 0.05-0.1% weight PLA, 0.05-0.1% PHA, 0.05-0.1% PBAT,0.10-0.20 weight % PBS, 0.01 by weight % silicon dioxide, andcombinations of these compositions.
 35. A method of making fibers,comprising: blending a masterbatch consisting essentially of 0.2 to 5mass % CaCO₃; an aliphatic polyester comprising a repeat unit havingfrom two to six carbons in the chain between ester groups, with theproviso that the 2 to 6 carbons in the chain do not include side chaincarbons; and a carrier polymer selected from the group consisting ofPET, nylon, olefins, other thermoplastic polymers, and combinationsthereof; into a polymer selected from the group consisting of PET,nylon, olefins, other thermoplastic polymers, and combinations thereofto form a molten mixture; and thereafter extruding the mixture asfilament.
 36. A method of making fibers according to claim 35 comprisingadding the masterbatch to a polymer production line after the polymerhas been made, but while the polymer remains in the molten state.
 37. Amethod of making fibers according to claim 35 comprising adding themasterbatch to a continuous polymer line during polymerization of thetarget polymer.
 38. A method of making fibers according to claim 35further comprising quenching the extruded filament.
 39. A method ofmaking fibers according to claim 38 further comprising texturing thefilament.
 40. A method of making fibers according to claim 39 comprisingcutting the textured filament into staple fibers.
 41. A method of makingfibers according to claim 40 further comprising spinning the staplefibers into yarn.
 42. The method of claim 41 further comprising weavingthe yarn into fabric.
 43. The method of claim 41 further comprisingknitting the yarn into fabric.
 44. The method of claim 40 furthercomprising laying a nonwoven batt from the staple fibers.
 45. The methodof claim 35 further comprising the step of extruding the molten mixtureas pellets, and thereafter remelting the pellets prior to the step ofextruding the mixture to form fibers.
 46. A method according to claim 35wherein the masterbatch to be blended consists essentially of: between0.9 and 1.1 mass percent calcium carbonate; and wherein the 2-6 carbonaliphatic ester is polycaprolactone in an amount of 44-54 mass percent;further comprising polybutylene succinate in an amount of 9-11 masspercent; and with the remainder of the masterbatch being polyethyleneterephthalate as the carrier polymer.
 47. A composition particularlysuitable for masterbatch formulation of synthetic polymers, saidmasterbatch consisting essentially of: 49% by weight of the totalcomposition polycaprolactone; 40% by weight of the total compositionpolyester; 10% by weight of the total composition polybutyl succinate;and 1% by weight of the total composition calcium carbonate.
 48. Thecomposition according to claim 47 consisting essentially of: 39-48weight % polyester; 39-49 weight % PLC; and 1 weight % calciumcarbonate.
 49. The composition according to claim 48 further comprisinga composition selected from the group consisting of 5-10% weight PLA,5-10 weight % PHA, 5-10 weight % PBAT, 10-20 weight % PBS, 1 by weight %silicon dioxide, and combinations of these compositions.
 50. A textilefilament comprising: polycaprolactone 0.49% by weight; polybutylsuccinate 0.1% by weight; calcium carbonate 0.01% by weight and; withthe remainder polyester.
 51. A filament according to claim 50 consistingessentially of: 0.39-0.48 weight % polyester; 0.39-0.49 weight % PLC;and 0.01 weight % calcium carbonate; and at least 90 mass % PET.
 52. Afilament according to claim 51 and further comprising a compositionselected from the group consisting of 0.05-0.1% weight PLA, 0.05-0.1%PHA, 0.05-0.1% PBAT, 0.10-0.20 weight % PBS, 0.01 by weight % silicondioxide, and combinations of these compositions
 53. An improved polarfleece in which the soft napped insulating fabric is made from: analiphatic polyester, other than PET, comprising a repeat unit havingfrom two to six carbons in the chain between ester groups, wherein the 2to 6 carbons in the chain does not include side chain carbons; 0.01 to0.2 mass % CaCO₃; and at least 90 mass % PET, nylon, olefins, otherthermoplastic polymers, and combinations thereof.
 54. An improved polarfleece according to claim 53 in which said soft napped insulating fabricis made from: polycaprolactone 0.49% by weight; polybutyl succinate 0.1%by weight; calcium carbonate 0.01% by weight; and with the remainderpolyester.
 55. A knitted polar fleece according to claim 53 wherein saidfabric is selected from the group consisting of woven fabrics andknitted fabrics.
 56. An insulated garment comprising: a shell; and afiber filling enclosed in said shell in which the fibers consistessentially of [an aliphatic polyester, other than PET, comprising arepeat unit having from two to six carbons in the chain between estergroups, wherein the 2 to 6 carbons in the chain does not include sidechain carbons; 0.01 to 0.2 mass % CaCO₃; and at least 90 mass % PET,nylon, olefins, other thermoplastic polymers, and combinations thereof.57. An insulated garment according to claim 56 wherein said filingfibers consist essentially of polycaprolactone 0.49% by weight;polybutyl succinate 0.1% by weight; calcium carbonate 0.01% by weightand; with the remainder polyester.
 58. A carpet comprising: a backing;and a yarn fixed to said backing; said yarn consisting essentially of analiphatic polyester, other than PET, comprising a repeat unit havingfrom two to six carbons in the chain between ester groups, wherein the 2to 6 carbons in the chain does not include side chain carbons; 0.01 to0.2 mass % CaCO₃; and at least 90 mass % PET, nylon, olefins, otherthermoplastic polymers, and combinations thereof.
 59. A carpet accordingto claim 58 wherein said yarn consists essentially of polycaprolactone0.49% by weight; polybutyl succinate 0.1% by weight; calcium carbonate0.01% by weight and; with the remainder polyester.